Designing Hexagonal Architecture with Java [2 ed.] 9781837635115

Table of contents :
Designing Hexagonal Architecture with Java
Contributors
About the author
About the reviewers
Preface
Who this book is for
What this book covers
To get the most out of this book
Download the example code files
Conventions used
Get in touch
Share Your Thoughts
Download a free PDF copy of this book
Part 1: Architecture Fundamentals
1
Why Hexagonal Architecture?
Technical requirements
Reviewing software architecture
Making decisions
The invisible things
Technical debt
Vicious cycle
It’s not for everyone
Monolithic or distributed
Understanding hexagonal architecture
Domain hexagon
Application hexagon
Use cases
Output ports
Framework hexagon
Advantages of the hexagonal approach
Summary
Questions
Further reading
Answers
2
Wrapping Business Rules inside Domain Hexagon
Technical requirements
Modeling a problem domain with entities
The purity of domain entities
Relevant entities
Using UUIDs to define identity
Enhancing descriptiveness with value objects
Using value objects to compose entities
Assuring consistency with aggregates
Modeling an aggregate
Working with domain services
Using policy and specification to deal with business rules
Creating specifications
Creating policies
Defining business rules as POJOs
Summary
Questions
Further reading
Answers
3
Handling Behavior with Ports and Use Cases
Technical requirements
Expressing software behavior with use cases
How to create a use case
Implementing use cases with input ports
Using output ports to deal with external data
It’s not only about repositories
Where to use output ports
Automating behavior with the Application hexagon
Summary
Questions
Further reading
Answers
4
Creating Adapters to Interact with the Outside World
Technical requirements
Understanding adapters
Using input adapters to allow driving operations
Creating input adapters
Using output adapters to speak with different 
data sources
Creating output adapters
Summary
Questions
Answers
Further reading
5
Exploring the Nature of Driving and Driven Operations
Technical requirements
Reaching the hexagonal application with driving operations
Integrating web applications with the hexagonal system
Creating the Add Network page
Creating the Get Router page
Running test agents
Calling the hexagonal system from other applications
Handling external resources with driven operations
Data persistence
Messaging and events
Mock servers
Summary
Questions
Answers
Part 2: Using Hexagons to Create a Solid Foundation
6
Building the Domain Hexagon
Technical requirements
Bootstrapping the Domain hexagon
Understanding the problem domain
Defining value objects
Defining entities and specifications
The Equipment and Router abstract entities
The core router entity and its specifications
Edge router entity and its specifications
Switch entity and its specifications
Defining domain services
Router service
Switch service
Network service
Testing the Domain hexagon
Summary
Questions
Answers
7
Building the Application Hexagon
Technical requirements
Bootstrapping the Application hexagon
Defining use cases
Creating written descriptions for router management use cases
Defining the use case interface for router management
Creating written descriptions for switch management use cases
Defining the use case interface for switch management
Creating written descriptions for network management use cases
Defining the use case interface for network management
Implementing use cases with input ports
Testing the Application hexagon
Summary
Questions
Answers
8
Building the Framework Hexagon
Technical requirements
Bootstrapping the Framework hexagon
Implementing output adapters
The router management output adapter
The switch management output adapter
Implementing the input adapters
The router management input adapter
The switch management input adapter
The network management input adapter
Testing the Framework hexagon
Summary
Questions
Answers
9
Applying Dependency Inversion with Java Modules
Technical requirements
Introducing the JPMS
Inverting dependencies on a hexagonal application
Providing services with use cases and input ports
Providing services with output ports and output adapters
Making the input adapters dependent on abstractions
Using the Java platform’s ServiceLoader class to retrieve JPMS provider implementations
Initializing RouterManagementGenericAdapter
Initializing SwitchManagementGenericAdapter
Initializing NetworkManagementGenericAdapter
Summary
Questions
Answers
Further reading
Part 3: Becoming Cloud-Native
10
Adding Quarkus to a Modularized Hexagonal Application
Technical requirements
Revisiting the JVM
Speeding up runtime performance with JIT compilation
Improving startup time with AOT compilation
Introducing Quarkus
Creating REST endpoints with JAX-RS
Employing dependency injection with Quarkus DI
Validating objects
Configuring a data source and using Hibernate ORM
Adding Quarkus to a modularized hexagonal application
Summary
Questions
Answers
11
Leveraging CDI Beans to Manage Ports and Use Cases
Technical requirements
Learning about Quarkus DI
Working with beans
Transforming ports, use cases, and adapters into CDI beans
Implementing CDI for router management objects
Implementing CDI for switch management objects
Implementing CDI for network management classes and interfaces
Testing use cases with Quarkus and Cucumber
Summary
Questions
Answers
12
Using RESTEasy Reactive to Implement Input Adapters
Technical requirements
Exploring the approaches to handling server’s requests
Imperative
Reactive
Implementing input adapters with RESTEasy Reactive
Implementing the Reactive input adapter for router management
Implementing the Reactive input adapter for switch management
Implementing the Reactive input adapter for network management
Adding OpenAPI and Swagger UI
Testing Reactive input adapters
Summary
Questions
Answers
13
Persisting Data with Output Adapters and Hibernate Reactive
Technical requirements
Introducing Hibernate Reactive and Panache
Hibernate Reactive features
Panache features
Enabling reactive behavior on output adapters
Configuring reactive data sources
Configuring entities
Implementing reactive repository classes
Implementing reactive output adapters
Reactive router management of the MySQL output adapter
Reactive switch management of the MySQL output adapter
Testing the reactive output adapters
Summary
Questions
Answers
14
Setting Up Dockerfile and Kubernetes Objects for Cloud Deployment
Technical requirements
Preparing the Docker image
Creating a Docker image with an uber .jar artifact
Creating a Docker image with a native executable
Creating Kubernetes objects
Reviewing Kubernetes' main objects
Configuring Kubernetes objects for the hexagonal system
Deploying on minikube
Summary
Questions
Answers
Part 4: Hexagonal Architecture and Beyond
15
Comparing Hexagonal Architecture with Layered Architecture
Technical requirements
Reviewing the layered architecture
Creating an application using the layered architecture
Implementing the data layer
Implementing the service layer
Implementing the API layer
Testing the layered application
Refactoring a layered architecture application into a hexagonal one
Implementing the Domain hexagon
Implementing the Application hexagon
Implementing the Framework hexagon
Testing the hexagonal application
Assessing the benefits and disadvantages of hexagonal and layered architectures
Summary
Questions
Answers
16
Using SOLID Principles with Hexagonal Architecture
Technical requirements
Understanding SOLID principles
Single Responsibility Principle (SRP)
Open-Closed Principle (OCP)
Liskov Substitution Principle (LSP)
Interface Segregation Principle (ISP)
Dependency Inversion Principle (DIP)
Applying SOLID on a hexagonal architecture system
Applying the SRP
Applying the OCP
Applying the LSP
Applying the ISP
Applying the DIP
Exploring other design patterns
Singleton
Builder
Abstract factory
Summary
Questions
Answers
17
Good Design Practices for Your Hexagonal Application
Technical requirements
Using Domain-Driven Design to shape the Domain hexagon
Understanding the business we are in
Promoting collaboration to increase knowledge
Applying DDD techniques to build the Domain hexagon
Implementing bounded contexts and subdomains in a hexagonal system
The need for creating ports and use cases
Dealing with multiple adapter categories
Conclusion – the hexagonal journey
Summary
Questions
Answers
Index
Why subscribe?
Other Books You May Enjoy
Packt is searching for authors like you
Share Your Thoughts
Download a free PDF copy of this book

Polecaj historie

Designing Hexagonal Architecture with Java: Build maintainable and long-lasting applications with Java and Quarkus [Team-IRA] 1837635110, 9781837635115

Learn to build robust, resilient, and highly maintainable cloud-native Java applications with hexagonal architecture and

786 90 4MB Read more

Test-Driven Development with Java: Create higher-quality software by writing tests first with SOLID and hexagonal architecture 9781803236230, 180323623X

Drive development with automated tests and gain the confidence you need to write high-quality software Key FeaturesGet u

155 101 11MB Read more

Designing with Data 9781449334833

On the surface, design practices and data science may not seem like obvious partners. But these disciplines actually wor

185 41 13MB Read more

Get Programming with Java

3,572 772 9MB Read more

Loose-Fit Architecture: Designing Buildings for Change 9781119152651, 9781119463344

Loose-Fit Architecture: Designing Buildings for Change September/October 2017 Profile 249 Volume 87 No 5 ISBN 978 1119 1

215 36 77MB Read more

Designing for the Homeless: Architecture That Works 9780520929258, 9780520235250

Written by an architect who has been designing and building affordable housing for thirty years, this well-illustrated b

188 114 59MB Read more

Neural Network Programming with Java

Unleash the power of neural networks by implementing professional Java code

0 0 6MB Read more

Real-time Java programming with Java RTS 9780137142989, 0137142986

The Definitive Guide to Java RTS for Developers and Architects For Java developers and architects moving to real-time, a

1,679 206 3MB Read more

Java: Learn Complete Java Programming with Fun. 9781500863296, 1500863297

Essential Java Skills—Made Easy! Learn the all basics and advanced features of Java programming in no time from Bestse

524 112 2MB Read more

Java: Learn Java Programming With Ultimate Zero to Hero Programming Crash Course for Beginners (Java, Java Programming Language, Java Coding, Java for ... Java Programming for Beginners, JavaScript)

3,056 485 74KB Read more